Roast the garlic: In a baking dish add 2 cups garlic cloves and 3 cups olive oil. Cover tightly with foil and bake at 350 degrees for 40 minutes. Cool, drain garlic, and purée. Reserve oil for other cooking uses.
Cook the spaghetti. Keep warm or boil while you make the clams.
Make the clams
Scrub clams.
Heat wine and clam juice in a sauté pan; add clams and cover. Cook until they open, about 5-7 minutes.
Add roasted garlic purée and butter. Toss well.
Add spaghetti, parmesan, lemon juice, and parsley. Season and enjoy.